Arthur schroeder



T. E. SPRINGMANN PROCESS FOR OBTAINING NITRIC OXIDE Aug. 2s, 1923. 1,466,604r

Filed NOV. l. 1922 Patented ug. 28, 1923.

' nutren erstes PATENT OFFICE.

THEODOR E. SPRINGMANN, OF CHALOTTENBURG, NEAR BERLIN, GERMANY.

rnociiss ron. on'riiriviive Nrrnio oxinn.

Application filed. November 1, 1922. Serial No. 598,434.

obtaining nitric o-xide'by heating fuel gas and air to ay temperature high enough to obtain, by burning the preheated fuel gas and air, a temperature at which nitric oxidek is formed, and then suddenly cooling the gas of combustion containing nitric oxide on water-cooled surfaces, such` as forexample. the walls or tubes ofia steam boiler. v

In known processes .of thisy kind` air is heated by electric discharges to the high 2O and the heated fluid is then suddenly cooled i on water-cooled surfaces. The heaty absorbed from the gases can be used for producing steam. A drawback of these-proc- 5 esses is that the heating of the gases by electricity is very expensive.

The object of this invention is to remove this drawback and. this is accomplished by producing the high temperature required 4for the combustion of oxygen and nitrogen 1 in a gas combustion chamber of steam boilers. by feeding the gas burner in the said combustion chamber with fuel gas and air which has been preheated by any devices for heating gases such as for example a regenerator or recuperator.

The speed of circulation of the water in the steam boiler may be increased if necessary by artificial means such as a rotary 10 pump in order to prevent the walls or tubes of the boiler being burnt through by the high temperature ofr combustion required for the process, this temperature being much higher than that in ordinary furnaces.

5 boiler furnace is preferably madedependent on the said circulation. This can be effecttemperature at which nitric oxide is formed,

In order to prevent the said burningy ed for exampleby throttling thepreheated gas and air conducted into the furnace, or by conducting cold fuel gas into the furnace. lShould it not be possible to main- Vtain the .circulation 0f the water during the working of the plant, the boiler may be kept inoperation solely by means of gas and air whichhas not been preheated.

In contradistinction Vfrom other known processes for obtaining nitric oxide,- the high temperature required for the combustion of 4`nitrogen according to the new process is produced in a very economical manner, because lonly 'veryy little of the heat of the fuel is lost in the process of obtaining the high itemperature necessary to obtain nitric oxide, while in producing the necessary advantage ofthe new process is that, in addition to obtaining nitric oxide, commer- 'heat by electricity only a small fraction of 'Y the heat vof the fuel is utilized. Anothery cial high pressure steam is obtained very i economically in a perfectly reliable boiler plant. A niuoh smaller heating surface than in ordinary boilers is required to produce the saine quantity of steam on account of the rate of evaporation being increased to a large extent by the very high temperature and the great speed of flow of water and combustion gas. The invention is rillustrated companied drawing in whichy Fig. l is a diagrammatic horizontal fsecin the action through the plant, and shows the gas heating devices in the form Yof regenerators and a boiler with vertical water tubes.

Fig. f 2 an endl elevation of a boiler equipped with an artificial means for increasing circulation, this means consisting `of a rotary pump.

the regenerators, while they are being' heated. 7, 9, 1l, 13 are valves for controlling and stopping the flow of air and 8, l0, 12 and 14 are similar valves for controlling and stopping the flow of fuelA gasinto the regeneration The gas enters a distributing pipe at and *the air enters a distributingpipe at 16. l

17 and 1S are valves 'for stoppingthe flow of gas from the regeneratorsinto a pipe leading to a burner 21 in the furnace or' the boiler and 19` 29 are simiiar valves for` Y valves for stopping` the flow ot combustion gases et the regeneretors from the regenerators into the chimneys and 2S, 29 are auxiliary valves for controlling' the flow of air and gas through a by-path tothe burner 'so as to venable gas and air Which is not pre 4heated inthe .regenerators to be supplied to 'the burner 21.v

Gas and air may be sent alternately `through pairs of heat exchangers in the fol* lowing manner: In the first period of Worl'e ingr the air valves 7 and 11, the gas valves Sand 12, and the chimney valves 24- and 26 are opened, While the valves 17 and 19 leadingto the'burner are closed. Fuel gas and air will then burn in the reggeneratorsV 1 and 3, the Vgases et combustion escaping` through the chimney valves 24 and 26 into the chimneys and 6 or fines. 'The air and gas vburnt in the regenerators 1 and 3 will produce heat and raise the temperature to the desired point.

At the same time the `gas valve 10 and the air valve 18 and also the valves 18 and 2O are opened, Whilethe chimney valves 25 and 27. the gas valve 141 and the air valve 9 are closed. Hence gas Will flow through the regenerator 2 and air through the regenerator l which will impart the heat generated in them during the previous heat-ing period to the gas and air. The gas and air are brought to a high temperature and `pass through the valves 18, 20 to the burner 21 in the furnace of the steam boiler. The combustion oit the preheated gas and air at the burner gives rise to temperatures that are so high that nitric oxide is formed. rlhe sudden cooling of the gases containing` nitric oxide by the pipes 22 o't the steam boiler prevents the formed nitric oxides from decomposing into their component parts. rThe cooled combustion gases containing' nitric oxide pass Athrough the combustion gas flue 2-3to the apparatus in which the nitric oxides are Washed out.

-Regenerators 2 and 4 preheat fuel gas and air and so arecooled in the same measure as the regenerators 1 and 23 are being heated atthesametime, unti-lthe various valves are operated te start the second or next period in the process.

-neys 5 and G.

Second period: rhe air valves 9 and 13, the gas valves 10 and 14, and also the Chim ney valves 25 and 27 are opened, While the valves 18 and 2O are closed. VConsequently gas and air will be burnt in the regeneretors 2 and 4;, and the burnt gases pass out through the chimney valves 25 and 27 into the chim- `The refrenerators 2 and 1, Whose temperature was lowered duriimT the .first period,are noiv heated up to the temperature required for subsequently preheating the air and gas to be passed through them.

At the same time the air valve 7, gas valve 12 and chimney valves 2e, 26 are closed, While the valves 17 and 19 are opened. Consequenty gas will flow through the regenerate-r 1 and airthrough the regenerator 3Vso that lthese regenerators Will noiv impart Ythe heat which they have received durthe iii-st period to the gas and air passing through them. The gas and air passes through the valves 17 and 191to the burner 21'in the boiler furnace Where they are burnt.

'ln the further working of the process the diierent periods alternate in the manner described for the two periods.

Should it 'be necessary to lower the temperature oficombustion in the boiler, air and gas which have not been preheated may be introduced into the boiler 'furnace through bypasses controlled'by the valves 28 and 29.

En some cases the temperature of combustion required for ythe 'formation of nitric oxide may be obtained by preheating;` the air or the tue] gras only.

in Fig'. 2 the manner in which the speed oi circulation ot the Water in the boilertubes can be lincreased by artificial means is shown. pipe a connects the top boiler 7 with the Vbottom'boiler c, and a rotary rpump .IZ vis provided in the pipe, which pnnp may be driven by an electromotor or .similar device..

rl`he heating' device for preheatinfr the gases may be ot any preferred type. Thus, instead of using a regenerator in which a iirehrick lining' alternately receives and yields up vheat from. or to a medium or duid which is in direct contact With the said lining', a recuperator may be employed through which the tivo mediums (the one Which receives heat-and the other Which imparts heat) lion' continuously i-n separate Channels seperated by `a dividing Wall which conducts heat `from the onegas to the other.

Many varia-tions of the plantI used for y ing out this process are `possible Without departing` Ifrom the scope of the invention.

Process for obtaining nitric oxide, comprising preheating both fuel gas and air .to

i' a temperature high enough to'obtain by as to prevent dissociation of the nitric oxide burning the gases a temperature at whichv which it contains.

nitric oxide is formed andkeeping the gases In testimony whereof I have afliled my entirely separate from each other `during the signature in presence yof two Witnesses. preheating, burning the gases, and cooling t THEO. E. SPRINGMANN. the gas ot Combustion immediately after it Witnesses:

is formed by bringing it into direct Contact E. HOLTZGRUM,

With the outer surface of a steam boiler so kARTHUR SCHROEDER. 

